Fibre drafting cots, aprons and the like



G. E. WATTS 2,816,326

FIBRE DRAFTING co'rs, APRONS AND THE LIKE Dec. 17, 1957 Filed Dec. 10,1953 -INVENTOR 645E firm 37 MAvzs,

BY I y ATTOR EKS FIBRE DRAFTING COTS, APRONS AND THE'L-IKEGilbertzErnest Watts, Marfleet, Hull, Yorkshire, England, I

:assignor to Resilla Cots and Rollers Limited Application December 10,1953, Serial No. 397,478

Claims priority, application Great Britain December 15, 1952 8 Claims.(Cl. 19--143) This invention relates to cots, aprons and the like usedin fibre drafting mechanisms. It is already known to use varioussynthetic rubber-like materials for this purpose and to incorporate inthem fillers or improvers which render them less liable to cause lappingof the textile fibres, or to suffer from what is called eyebrowformation with these fibres. Among the synthetic rubber-like materialsrecommended for this purpose have been chloroprene andbutadiene-acrylonitrile copolymers, and among the fillers or improversrecommend-ed have been animal proteins such as glue, gelatin, casein andalbumen.

I have now found that particularly favourable results are secured if thesynthetic rubber is mixed with a waterso-luble salt of alginic acid,which is readily obtainable and is easily mixed with the syntheticrubber in standard types of mixing machines. A comparatively smalladdition of sodium alginate or other water-soluble salt of alginic acidto the synthetic rubber selected produces a marked improvement in itsresistance to fibre lapping on roller cots, aprons and the like having asurface layer of the mixture. At the same time, the synthetic rubberretains its advantages in regard to wear resistance, absence of attackby oil and so forth.

Other fillers such as cork or whiting may be added for their usualpurposes, but it is the alginate which is of particular importance fromthe point of view of lapping prevention. The amount of alginate added tothe synthetic rubber may, with advantage, be of the order of 20% to 25%of the weight of the synthetic rubber compound, although largerproportions may be used, or smaller proportions down to about 10% ifsuch a high resistance to lapping is not required as is obtainable withthe larger proportions. The alginate may be added as a powder to therubber mix, or it can be added as an aqueous or other solution, in whichcase the solvent is evaporated during the mixing operation, leaving thealginate very finely distributed in the rubber-like compound. When thealginate is introduced in solution form, it improves the quality of thecots and aprons as regards the repelling of oil.

Sodium alginate is readily soluble in water and for some purposes,particularly to prevent eyebrow formation, it is desirable that thesurface of the cot or apron should be honeycombed or pitted, or at leastsomewhat irregular. This result can readily be attained by immersing thecot or apron for a short time in steam or a solvent liquid so as todissolve out particles of the alginate near the surface while leavingsufficient of the alginate in the body of the cot or apron to attain itsother intended purposes.

Another factor in the normal uses of cots is the prevention orlimitation of condensation of moisture which is liable to occur undercertain atmospheric conditions and interferes with the effective drawingof the fibres. The fact that the sodium alginate or other water-solublesalt of alginic acid readily absorb-s moisture enables it to take upcondensed moisture and to prevent such mois- 2,8 1 6,326 Tate'rite'dDec. .17, T?

ture from'afiectin g;the "drawing 1 or "other manipulation of "the'fibresin'contact with it. Although cots have been re-:'ferred=*to1above,"it is clearly 'tobe understood that the same-"factors "arise with apronsan'd-other drafting surfaces for textilefibres. I a 7 Anotherdifiiciilty which arises inthe operation of pots"or aprons formed of synthetic rubber, when .used .with

.textile "'fibres, "particularly cottonjis thatfforeign matteriassociated;with"thefibres tends to collect on .the cots-.'a-nd "aprons,f-resulting in time in causing fibres to. adheraso that lapping results."An advantageo'f the use-ofi-alginates admixed with synthetic rubbermaterial, 'is "that the foreign matter which tends to collect on theactive surface is thrown ofi where it comes in contact with the alginateparticles in the presence of moisture. Although it is possible in manycases to clean off such foreign matter by washing operations, butfingand so forth, it is an advantage to be able to use a material whichrenders such additional operations largely unnecessary.

Although sodium alginate has been referred to throughout as thepreferred form of alginate for use because it is readily available, Ihave obtained satisfactory results with the use of other water-solublesalts of alginic acid, such as ammonium alginate, or alginates oforganic bases, e. g. triethanolamine alginate.

In the drawing:

Fig. 1 is a perspective of a top spinning roller or cot with thecovering broken away at one end;

Fig. 2 is a section along line Z2 of Figure 1 looking in the directionof the arrows;

Fig. 3 is a perspective of one end of the spinning cot sleeve;

Fig. 4 is a section on line 4-4 of Fig. 3 looking in the direction ofthe arrows;

Fig. 5 is a section on line 5-5 of Fig. 3 looking in the direction ofthe arrows; and

Fig. 6 is a perspective of one end of a modified form of spinning cotsleeve according to the invention which is provided with a pittedsurface.

In the drawing, 1 is the synthetic rubber cot sleeve having a watersoluble salt of alginic acid incorporated therein and 2 is the corewhich is usually composed of metal.

In the modification of the cot sleeve shown in Fig. 6, the surface ofcot sleeve 3 has been provided with pits 4 by immersing the sleeve for ashort time in steam or a solvent liquid so as to dissolve out particlesof the alginate near the surface while leaving sufficient amounts of thealginate in the body of the cot sleeve to attain its other intendedpurposes.

I claim:

1. In a machine for drafting textile fibres, a fibre drafting elementhaving a fibre contacting surface composed of a synthetic rubber havingincorporated therein a watersoluble salt of alginic acid.

2. In a machine for drafting textile fibres, a fibre drafting element asclaimed in claim 1, in which the synthetic rubber is chloroprene.

3. In a machine for drafting textile fibres, a fibre drafting element asclaimed in claim 1, in which the synthetic rubber isbutadiene-acrylonitrile copolymer.

4. In a machine for drafting textile fibres, a fibre drafting element asclaimed in claim 1 in which the water-soluble salt of an alginic acid isselected from the group consisting of sodium alginate, ammonium alginateand triethanolamine alginate.

5. In a machine for drafting textile fibres, a fibre drafting element asclaimed in claim 1 and having a lightly pitted surface.

6. In a machine for drafting textile fibres, a fibre drafting elementhaving a fibre contacting surface composed of a synthetic rubber havingabout 20 to 25% of a water-soluble salt of alginic acid incorporatedtherein.

7. A process for producing a surface covering for a drafting roller, inwhich process a covering element composed of synthetic rubberhavingincorporated therein a water-soluble salt of alginic: acid issubjected to treatment with a solvent for said 'salt to dissolve outparticles of said salt at the surface of such covering element and toproduce a pitted surface thereon.

8. In the production of a fibre contacting element to cover at least oneroller in a textile fibre drafting machine, the steps comprisingpreparing a synthetic rubber mix, incorporating a solution of awater-soluble salt of alginic acid in a solvent in said mix, removingthe solvent and forming said rubber mix into said fibre contactingsurface;

References Cited in the file of this patent UNITED STATES PATENTS Adamset a1. Dec. 1, Rockofi Dec. 8, Holtzdow Oct. 26, Bender Nov. 26,Rockofl? Mar. 9, Golden Dec. 28, Rhines Sept. 13, Rockofi Mar. 14,Mersereau May 5,

1. IN A MACHINE FOR DRAFTING TEXTILE FIBRES, A FIBRE DRAFTING ELEMENTHAVING A FIBRE CONTACTING SURFACE COMPOSED OF A SYNTHETIC RUBBER HAVINGINCORPORATED THEREIN A WATERSOLUBLE SALT OF ALGINIC ACID.